Stabilization systems known up to now operate in accordance with the electromechanical principle with a cardanic suspension of the sensor while driving the positioning motors via an inertial sensor; or, CCD sensors are utilized when making aerial image recordations without stabilization. Here, a migration of the images must be accepted for a line sensor between the lines or between frames with an area sensor. This image migration is caused by disturbing movements of the carrier.
Generally, it is possible to provide image stabilization on board or in a ground station. In the first case, there is an on-line stabilization for display on a monitor and, in the second case, there is an off-line image evaluation. As a rule, the on-line stabilization is carried out. This takes place with area sensors in camcorders. An on-line correction is carried out and analog signal processing takes place.
For example, European patent publication 0,543,394 discloses that, for an area sensor, the movements occurring at the time point of the exposure are corrected on-line in a frequency range of 1 to 12 Hz. The correction takes place via an optical element. The correcting signals are determined via two sensors which each measure the angular acceleration or the angular velocity.
Furthermore, U.S. Pat. No. 5,396,286 discloses the determination of vibrations in the horizontal and vertical directions. Here, an on-line correction is made either via readdressing or reading out from a storage register at a lower frequency than for writing.
Finally, U.S. Pat. No. 4,959,725 discloses a very complex circuit for correcting the video signal of an area sensor while performing an evaluation with accelerometers.
However, all known solutions of the state of the art cannot be characterized as optimal with respect to their commercial effectiveness because of the high cost associated therewith.